Method for forming thin film

ABSTRACT

According to the present invention, it is possible to suppress side reactions to appropriately lower a thin film growth rate and remove process byproducts in the thin film, thereby preventing corrosion or deterioration and greatly improving step coverage and thickness uniformity of a thin film, even when the thin film is formed on a substrate having a complex structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to Korean PatentApplication No. 10-2019-0118417, filed on Sep. 25, 2019, and KoreanPatent Application No. 10-2019-0137838, filed on Oct. 31, 2019, in theKorean Intellectual Property Office, the disclosures of which areincorporated herein by reference in their entirety.

TECHNICAL FIELD

The following disclosure relates to a method for forming a thin film,and more particularly, to a method for forming a thin film capable ofsuppressing side reactions to appropriately lower the thin film growthrate and remove process byproducts in the thin film, thereby preventingcorrosion or deterioration and greatly improving the step coverage andthickness uniformity of a thin film even when the thin film is formed ona substrate having a complex structure.

BACKGROUND

The degree of integration of memory and non-memory semiconductor devicesis increasing day by day. As the structure thereof becomes more and morecomplex, the importance of step coverage in the deposition of variousthin films on a substrate is gradually increasing.

A thin film for a semiconductor is made of a metal nitride, metal oxide,metal silicide, or the like. Metal nitride thin films include titaniumnitride (TiN), tantalum nitride (TaN), zirconium nitride (ZrN), and thelike. The thin films are generally used as a diffusion barrier betweenthe silicon layer of a doped semiconductor and an interlayer wiringmaterial such as aluminum (Al), copper (Cu), or the like. However, whena tungsten (W) thin film is deposited on the substrate, the tungsten (W)thin film is used as an adhesion layer.

In order to obtain a thin film having excellent and uniform physicalproperties when deposited on the substrate, it is essential that theformed thin film have a high step coverage. Therefore, an atomic layerdeposition (ALD) process employing a surface reaction, rather than achemical vapor deposition (CVD) process mainly employing a gas phasereaction, is utilized; however, there are still problems for realizationof 100% step coverage.

In addition, in the case of using titanium tetrachloride (TiCl₄) todeposit titanium nitride (TiN), a representative material among themetal nitrides, process by-products such as chlorides remain in theprepared thin film, causing corrosion of metals such as aluminum, andthe like, and the production of non-volatile byproducts leads todeterioration of film quality.

Therefore, it is necessary to develop a method for forming a thin filmwhich is capable of forming a thin film having a complex structure andwhich does not lead to corrosion of an interlayer wiring material.

Documents of the Related Art

(Patent Document 1) Korean Patent Laid-Open Publication No. 2006-0037241

SUMMARY

An embodiment of the present disclosure is directed to providing amethod for forming a thin film capable of suppressing side reactions toappropriately lower the growth rate of the thin film and remove processbyproducts therein, thereby preventing corrosion or deterioration andgreatly improving the step coverage and thickness uniformity of the thinfilm, even when the thin film is formed on a substrate having a complexstructure.

All of the above objects and other objects of the present disclosure canbe achieved by the present disclosure described below.

To achieve the above-mentioned objects, the present disclosure presentsa method for forming a thin film comprising steps of:

i) adsorbing a growth inhibitor for forming a thin film on a surface ofa substrate; and ii) adsorbing a metal film precursor, metal oxide filmprecursor, metal nitride film precursor or silicon nitride filmprecursor on a surface of a substrate on which the growth inhibitor isadsorbed, wherein the growth inhibitor for forming a thin film isrepresented by Chemical Formula 1 below, and the metal is at least oneselected from a group consisting of tungsten, cobalt, chrome, aluminum,hafnium, vanadium, niobium, germanium, lanthanide, actinoids, gallium,tantalum, zirconium, ruthenium, copper, titanium, nickel, iridium andmolybdenum.

AnBmXo  [Chemical Formula 1]

wherein A is carbon or silicon, B is hydrogen or a C1-C3 alkyl, X is ahalogen, n is an integer of 1 to 15, o is an integer of 1 or more, and mis 0 to 2n+1.

In addition, the present invention relates to an apparatus for preparinga thin film, comprising an atomic layer deposition (ALD) chamber, afirst vaporizer for vaporizing the growth inhibitor for forming a thinfilm, a first transfer unit for transferring the vaporized growthinhibitor into the ALD chamber, a second vaporizer for vaporizing ametal film precursor, metal oxide film precursor, metal nitride filmprecursor or silicon nitride film precursor, and a second transfer unitfor transferring the vaporized thin film precursor into the ALD chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a process chart illustrating a conventional atomic layerdeposition (ALD) process.

FIG. 2 is a flowchart illustrating an ALD process according to anembodiment of the present disclosure.

FIG. 3 is a graph illustrating the change in thin film thicknessaccording to the increase in ALD cycle for Example (SP—TiCl₄) andComparative Example 1 (TiCl₄) of the present disclosure.

FIG. 4 is a graph illustrating the change in deposition rate accordingto feeding time of growth inhibitor (SP) for forming a thin film per ALDcycle for Examples 7-1 to 7-3 and Comparative Example 1 of the presentdisclosure.

FIG. 5 illustrates transmission electron microscope (TEM) images of TiNthin films deposited for Example 1 (SP—TiCl₄) and Comparative Example 1(TiCl₄) of the present disclosure.

FIG. 6 is a graph illustrating the change in deposition rate (Å/cycle)according to feeding time (s) of a growth inhibitor (SP) for forming athin film per ALD cycle for Additional Example 2 and AdditionalComparative Example 1 of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, a method for forming a thin film is described in detail.

The present inventors found that when a halogen-substituted compoundhaving a predetermined structure is first adsorbed as a growth inhibitorbefore the adsorption of a thin film precursor compound on a surface ofa substrate loaded inside an atomic layer deposition (ALD) chamber, thegrowth rate of the thin film to be formed after deposition is loweredand a significant reduction of the halides remaining as processbyproducts is achieved, thereby greatly improving step coverage, and thelike. Based on this finding, the present inventors made a significanteffort on further research and thereby completed the present disclosure.

The method for forming a thin film of the present disclosure ischaracterized by comprising steps of i) adsorbing a growth inhibitor forforming a thin film on a surface of a substrate; and ii) adsorbing ametal film precursor, metal oxide film precursor, metal nitride filmprecursor or silicon nitride film precursor on a surface of a substrateon which the growth inhibitor is adsorbed, wherein the growth inhibitorfor forming a thin film is represented by Chemical Formula 1 below, andthe metal is at least one selected from a group consisting of tungsten,cobalt, chrome, aluminum, hafnium, vanadium, niobium, germanium,lanthanide, actinoids, gallium, tantalum, zirconium, ruthenium, copper,titanium, nickel, iridium and molybdenum.

AnBmXo  [Chemical Formula 1]

wherein A is carbon or silicon, B is hydrogen or a C1-C3 alkyl, X is ahalogen, n is an integer of 1 to 15, o is an integer of 1 or more, and mis 0 to 2n+1. In this case, side reactions occurring during formation ofthe thin film may be suppressed to lower the thin film growth rate whilealso achieving removal of process byproducts in the thin film, and thuscorrosion or deterioration may be reduced and step coverage andthickness uniformity of a thin film may be greatly improved even whenthe thin film is formed on a substrate having a complex structure.

In the step of i) adsorbing the growth inhibitor for forming a thin filmon the surface of the substrate, the feeding time per cycle for thegrowth inhibitor is preferably 1 to 10 seconds, more preferably 1 to 5seconds, even more preferably 2 to 5 seconds, and still more preferably2 to 4 seconds. Within this range, there are advantages in that the thinfilm growth rate is low, and the step coverage and economic feasibilityare excellent.

The feeding time of the growth inhibitor for forming a thin film in thepresent disclosure is based on a chamber having a volume of 15 to 20 Lat a flow rate of 0.5 to 5 mg/s, and more specifically, a chamber havinga volume of 18 L at a flow rate of 1 to 2 mg/s.

The step of i) adsorbing the growth inhibitor for forming a thin film onthe surface of the substrate may preferably comprise a step of injectingthe growth inhibitor for forming a thin film into an atomic layerdeposition (ALD) chamber and adsorbing the growth inhibitor onto asurface of a loaded substrate, and thereby suppressing side reactions,lowering the deposition rate to lower the growth rate of the thin film,and removing process byproducts in the thin film.

The step of i) adsorbing the growth inhibitor for forming a thin film onthe surface of the substrate may preferably comprise a step of purgingthe remaining inhibitor unadsorbed on a surface of the substrate forforming the thin film with a purge gas, and thereby suppressing sidereactions to lower the growth rate of the thin film and to removeprocess byproducts in the thin film, thereby greatly improving the stepcoverage and thickness uniformity of the thin film even when the thinfilm is formed on a substrate having a complex structure.

In addition, the step of ii) adsorbing a metal film precursor, metaloxide film precursor, metal nitride film precursor or silicon nitridefilm precursor (hereinafter ‘thin film precursor’) may preferablecomprise a step of purging the remaining unadsorbed thin film precursorwith a purge gas.

The method for forming a thin film may preferably comprise steps ofsupplying a reaction gas after adsorption of a thin film precursor onthe surface of the substrate, and purging reaction byproducts of thethin film precursor and the reaction gas with a purge gas.

In one preferred embodiment, the method for forming a thin film maycomprise steps of: a) vaporizing the growth inhibitor for forming a thinfilm and adsorbing the growth inhibitor on a surface of a substrateloaded in an atomic layer deposition (ALD) chamber; b) primary purgingof the inside of the ALD chamber with a purge gas; c) vaporizing a filmprecursor and adsorbing the thin film precursor compound on the surfaceof the substrate loaded in the ALD chamber; d) secondary purging of theinside of the ALD chamber with a purge gas; e) supplying a reaction gasinto the ALD chamber; and f) tertiary purging of the inside of the ALDchamber with a purge gas. In this case, there are advantages in that thethin film growth rate is appropriately lowered and the processbyproducts which may be generated are effectively removed even if thedeposition temperature is increased at the time of formation of the thinfilm, and thus the specific resistance of the thin film is reduced andthe step coverage is greatly improved.

The growth inhibitor for forming a thin film and the film precursor maypreferably be transferred into the ALD chamber, namely to the surface ofthe substrate, by a vapor flow control (VFC) method, a delivery liquidinjection (DLI) method or a liquid delivery system (LDS) method, and maymore preferably be transferred into the ALD chamber by the LDS method.

The ratio of the feeding amount (mg/cycle) between the growth inhibitorfor forming a thin film and the film precursor in the ALD chamber maypreferably be from 1:1.5 to 1:20, more preferably from 1:2 to 1:15, evenmore preferably from 1:2 to 1:12, and still more preferably from 1:2.5to 1:10. Within this range, a high reduction rate of the thin filmgrowth rate (GPC) per cycle and a great reduction of the processbyproducts may be achieved.

The film precursor to be employed is not particularly limited as long asit is a thin film precursor generally used in the ALD method.

The metal film precursor, the metal oxide film precursor, and the metalnitride film precursor may each be one or more selected from the groupconsisting of, for example, a metal halide, a metal alkoxide, an alkylmetal compound, a metal amino compound, a metal carbonyl compound, asubstituted or unsubstituted cyclopentadienyl metal compound, and thelike, but the precursor is not limited thereto.

As a specific example, the metal film precursor, the metal oxide filmprecursor, and the metal nitride film precursor may each be one or moreselected from the group consisting of tetrachlorotitan,tetrachlorogermanium, tetrachlorotin, tris(isopropyl)ethylmethylaminogermanium, tetraethoxylgermanium, tetramethyl tin, tetraethyl tin,bisacetylacetonate tin, trimethylaluminum,tetrakis(dimethylamino)germanium, bis(n-butylamino) germanium,tetrakis(ethylmethylamino) tin, tetrakis(dimethylamino)tin,Co₂(CO)₈(dicobalt octacarbonyl), Cp2Co(biscyclopentadienylcobalt),Co(CO)₃(NO) (cobalt tricarbonyl nitrosyl), and CpCo(CO)₂(cobaltdicarbonyl cyclopentadienyl and the like, but the precursor is notlimited thereto.

The silicon nitride film precursor, for example, may be one or moreselected from the group consisting of (NH₂)Si(NHMe)₃, (NH₂)Si(NHEt)₃,(NH₂)Si(NHnPr)₃, (NH₂)Si(NH^(i)Pr)₃, (NH₂)Si(NH^(n)Bu)₃,(NH₂)Si(NH^(i)Bu)₃, (NH₂)Si(NH^(t)Bu)₃, (NMe₂)Si(NHMe)₃,(NMe₂)Si(NHEt)₃, (NMe₂)Si(NH^(n)Pr)₃, (NMe₂)Si(NH^(i)Pr)₃,(NMe₂)Si(NH^(n)Bu)₃, (NMe₂)Si(NH^(i)Bu)₃, (NMe₂)Si(NH^(t)Bu)₃,(NEt₂)Si(NHMe)₃, (NEt₂)Si(NHEt)₃, (NEt₂)Si(NH^(n)Pr)₃,(NEt₂)Si(NH^(i)Pr)₃, (NEt₂)Si(NH^(n)Bu)₃, (NEt₂)Si(NH^(i)Bu)₃,(NEt₂)Si(NH^(t)Bu)₃, (N^(n)Pr₂)Si(NHMe)₃, (N^(n)Pr₂)Si(NHEt)₃,(N^(n)Pr₂)Si(NH^(n)Pr)₃, (N^(n)Pr₂)Si(NH^(i)Pr)₃,(N^(n)Pr₂)Si(NH^(n)Bu)₃, (N^(n)Pr₂)Si(NH^(i)Bu)₃,(N^(n)Pr₂)Si(NH^(t)Bu)₃, (NiPr₂)Si(NHMe)₃, (N^(i)Pr₂)Si(NHEt)₃,(N^(i)Pr₂)Si(NH^(n)Pr)₃, (N^(i)Pr₂)Si(NH^(i)Pr)₃,(N^(i)Pr₂)Si(NH^(n)Bu)₃, (N^(i)Pr₂)Si(NH^(i)Bu)₃,(N^(i)Pr₂)Si(NH^(t)Bu)₃, (N^(n)Bu₂)Si(NHMe)₃, (N^(n)Bu₂)Si(NHEt)₃,(N^(n)Bu₂)Si(NH^(n)Pr)₃, (N^(n)Bu₂)Si(NH^(i)Pr)₃,(N^(n)Bu₂)Si(NH^(n)Bu)₃, (N^(n)Bu₂)Si(NH^(i)Bu)₃,(N^(n)Bu₂)Si(NH^(t)Bu)₃, (N^(i)Bu₂)Si(NHMe)₃, (N^(i)Bu₂)Si(NHEt)₃,(N^(i)Bu₂)Si(NH^(n)Pr)₃, (N^(i)Bu₂)Si(NH^(i)Pr)₃,(N^(i)Bu₂)Si(NH^(n)Bu)₃, (N^(i)Bu₂)Si(NH^(i)Bu)₃,(N^(i)Bu₂)Si(NH^(t)Bu)₃, (N^(t)Bu₂)Si(NHMe)₃, (N^(t)Bu₂)Si(NHEt)₃,(N^(t)Bu₂)Si(NH^(n)Pr)₃, (N^(t)Bu₂)Si(NH^(i)Pr)₃,(N^(t)Bu₂)Si(NH^(n)Bu)₃, (N^(t)Bu₂)Si(NH^(i)Bu)₃,(N^(t)Bu₂)Si(NH^(t)Bu)₃, (NH₂)₂Si(NHMe)₂, (NH₂)₂Si(NHEt)₂,(NH₂)₂Si(NH^(n)Pr)₂, (NH₂)₂Si(NH^(i)Pr)₂, (NH₂)₂Si(NH^(n)Bu)₂,(NH₂)₂Si(NH^(i)Bu)₂, (NH₂)₂Si(NH^(t)Bu)₂, (NMe₂)₂Si(NHMe)₂,(NMe₂)₂Si(NHEt)₂, (NMe₂)₂Si(NH^(n)Pr)₂, (NMe₂)₂Si(NH^(i)Pr)₂,(NMe₂)₂Si(NH^(n)Bu)₂, (NMe₂)₂Si(NH^(i)Bu)₂, (NMe₂)₂Si(NH^(t)Bu)₂,(NEt₂)₂Si(NHMe)₂, (NEt₂)₂Si(NHEt)₂, (NEt₂)₂Si(NH^(n)Pr)₂,(NEt₂)₂Si(NH^(i)Pr)₂, (NEt₂)₂Si(NH^(n)Bu)₂, (NEt₂)₂Si(NH^(i)Bu)₂,(NEt₂)₂Si(NH^(t)Bu)₂, (N^(n)Pr₂)₂Si(NHMe)₂, (N^(n)Pr₂)₂Si(NHEt)₂,(N^(n)Pr₂)₂Si(NH^(n)Pr)₂, (N^(n)Pr₂)₂Si(NH^(i)Pr)₂,(N^(n)Pr₂)₂Si(NH^(n)Bu)₂, (N^(n)Pr₂)₂Si(NH^(i)Bu)₂,(N^(n)Pr₂)₂Si(NH^(t)Bu)₂, (N^(i)Pr₂)₂Si(NHMe)₂, (N^(i)Pr₂)₂Si(NHEt)₂,(N^(i)Pr₂)₂Si(NH^(n)Pr)₂, (N^(i)Pr₂)₂Si(NH^(i)Pr)₂,(N^(i)Pr₂)₂Si(NH^(n)Bu)₂, (N^(i)Pr₂)₂Si(NH^(i)Bu)₂,(N^(i)Pr₂)₂Si(NH^(t)Bu)₂, (N^(n)Bu₂)₂Si(NHMe)₂, (N^(n)Bu₂)₂Si(NHEt)₂,(N^(n)Bu₂)₂Si(NH^(n)Pr)₂, (N^(n)Bu₂)₂Si(NH^(i)Pr)₂,(N^(n)Bu₂)₂Si(NH^(n)Bu)₂, (N^(n)Bu₂)₂Si(NH^(i)Bu)₂,(N^(n)Bu₂)₂Si(NH^(t)Bu)₂, (N^(i)Bu₂)₂Si(NHMe)₂, (N^(i)Bu₂)₂Si(NHEt)₂,(N^(i)Bu₂)₂Si(NH^(n)Pr)₂, (N^(i)Bu₂)₂Si(NH^(i)Pr)₂,(N^(i)Bu₂)₂Si(NH^(n)Bu)₂, (N^(i)Bu₂)₂Si(NH^(i)Bu)₂,(N^(i)Bu₂)₂Si(NH^(t)Bu)₂, (N^(t)Bu₂)₂Si(NHMe)₂, (N^(t)Bu₂)₂Si(NHEt)₂,(N^(t)Bu₂)₂Si(NH^(n)Pr)₂, (N^(t)Bu₂)₂Si(NH^(i)Pr)₂,(N^(t)Bu₂)₂Si(NH^(n)Bu)₂, (N^(t)Bu₂)₂Si(NH^(i)Bu)₂,(N^(t)Bu₂)₂Si(NH^(t)Bu)₂, Si(HNCH₂CH₂NH)₂, Si((MeNCH₂CH₂NMe)₂,Si(EtNCH₂CH₂NEt)₂, Si(^(n)PrNCH₂CH₂N^(n)Pr)₂, Si(iPrNCH₂CH₂N^(i)Pr)₂,Si(^(n)BuNCH₂CH₂NnBu)₂, Si(iBuNCH₂CH₂N^(i)Bu)₂,Si(^(t)BuNCH₂CH₂N^(t)Bu)₂, Si(HNCHCHNH)₂, Sii (MeNCHCHNMe)₂,Si(EtNCHCHNEt)₂, Si(^(n)PrNCHCHN^(n)Pr)₂, Si(^(i)PrNCHCHN^(i)Pr)₂,Si(^(n)BuNCHCHN^(n)Bu)₂, Si (iBuNCHCHNiBu)₂, Si(^(t)BuNCHCHN^(t)Bu)₂,(HNCHCHNH)Si(HNCH₂CH₂NH), (MeNCHCHNMe)Si(MeNCH₂CH₂NMe),(EtNCHCHNEt)Si(EtNCH₂CH₂NEt),(^(n)PrNCHCHN^(n)Pr)Si(^(n)PrNCH₂CH₂N^(n)Pr),(^(i)PrNCHCHN^(i)Pr)Si(iPrNCH₂CH₂N^(i)Pr),(^(n)BuNCHCHN^(n)Bu)Si(^(n)BuNCH₂CH₂NnBu),(^(i)BuNCHCHN^(i)Bu)Si(^(i)BuNCH₂CH₂N^(i)Bu),(^(t)BuNCHCHN^(t)Bu)Si(^(t)BuNCH₂CH₂N^(t)Bu), (NH^(t)Bu)₂Si(HNCH₂CH₂NH),(NH^(t)Bu)₂Si((MeNCH₂CH₂NMe), (NH^(t)Bu)₂Si(EtNCH₂CH₂NEt),(NH^(t)Bu)₂Si(^(n)PrNCH₂CH₂N^(n)Pr),(NH^(t)Bu)₂Si(^(i)PrNCH₂CH₂N^(i)Pr),(NH^(t)Bu)₂Si(^(n)BuNCH₂CH₂N^(n)Bu),(NH^(t)Bu)₂Si(^(i)BuNCH₂CH₂N^(i)Bu),(NH^(t)Bu)₂Si(^(t)BuNCH₂CH₂N^(t)Bu), (NH^(t)Bu)₂Si(HNCHCHNH),(NH^(t)Bu)₂Si(MeNCHCHNMe), (NH^(t)Bu)₂Si(EtNCHCHNEt),(NH^(t)Bu)₂Si(^(n)PrNCHCHN^(n)Pr), (NH^(t)Bu)₂Si(^(i)PrNCHCHN^(i)Pr),(NH^(t)Bu)₂Si(^(n)BuNCHCHN^(n)Bu), (NH^(t)Bu)₂Si(^(i)BuNCHCHN^(i)Bu),(NH^(t)Bu)₂Si(^(t)BuNCHCHN^(t)Bu), (^(i)PrNCH₂CH₂N^(i)Pr)Si(NHMe)₂,(^(i)PrNCH₂CH₂N^(i)Pr)Si(NHEt)₂, (^(i)PrNCH₂CH₂N^(i)Pr)Si(NH^(n)Pr)₂,(^(i)PrNCH₂CH₂N^(i)Pr)Si(NH^(i)Pr)₂,(^(i)PrNCH₂CH₂N^(i)Pr)Si(NH^(n)Bu)₂,(^(i)PrNCH₂CH₂N^(i)Pr)Si(NH^(i)Bu)₂,(^(i)PrNCH₂CH₂N^(i)Pr)Si(NH^(t)Bu)₂, (^(i)PrNCHCHN^(i)Pr)Si(NHMe)₂,(^(i)PrNCHCHN^(i)Pr)Si(NHEt)₂, (^(i)PrNCHCHN^(i)Pr)Si(NH^(n)Pr)₂,(^(i)PrNCHCHN^(i)Pr)Si(NH^(i)Pr)₂, (^(i)PrNCHCHN^(i)Pr)Si(NH^(n)Bu)₂,(^(i)PrNCHCHN^(i)Pr)Si(NH^(i)Bu)₂ and (^(i)PrNCHCHN^(i)Pr)Si(NH^(t)Bu)₂,but is not limited thereto.

In the above, ^(n)Pr means n-propyl, ^(i)Pr means iso-propyl, ^(n)Bumeans n-butyl, ^(i)Bu means iso-butyl, and ^(t)Bu means tert-butyl.

In one preferred embodiment, the metal halide may be a titaniumtetrahalide, specifically, at least one selected from the groupconsisting of TiF₄, TiCl₄, TiBr₄, and TiI₄, and for example, from aneconomic standpoint, may more preferably be TiCl₄, but the titaniumtetrahalide is not limited thereto.

However, since the titanium tetrahalides do not decompose at roomtemperature but exist in a liquid state due to having excellent thermalstability, a titanium tetrahalide may be usefully employed for thedeposition of a thin film as the thin film precursor of ALD.

As an example, the film precursor may be mixed with a non-polar solventand injected into the chamber. In this case, there is an advantage inthat the viscosity or vapor pressure of the film precursor may be easilyadjusted.

The non-polar solvent may preferably be one or more selected from thegroup consisting of alkanes and cycloalkanes. In this case, there is anadvantage in that even when including an organic solvent having lowreactivity and solubility with easy moisture management capability, thestep coverage is improved even if the deposition temperature isincreased during formation of the thin film.

In a more preferred embodiment, the non-polar solvent may comprise a C1to C10 alkane or a C3 to C10 cycloalkane, and preferably a C3 to C10cycloalkane. In this case, there are advantages in that the reactivityand solubility are low and moisture management may be easily achieved.

In the present disclosure, the notations C1, C3, and the like, representthe number of carbons.

The cycloalkane may preferably be a C3 to C10 monocycloalkane. Among themonocycloalkanes, cyclopentane is a liquid at room temperature and hasthe highest vapor pressure, which is preferable in the vapor depositionprocess, but the solvent is not limited thereto.

The non-polar solvent has, for example, a solubility in water (25° C.)of 200 mg/L or less, preferably 50 to 200 mg/L, and more preferably 135to 175 mg/L. Within this range, there are advantages in that thereactivity for the thin film precursor is low and moisture managementmay be easily performed.

In the present disclosure, the method employed for the measurement ofsolubility is not particularly limited as long as the method orstandards thereof correspond to those generally used in the art to whichthe present disclosure pertains, and for example, a saturated solutionmay be measured by a high performance liquid chromatography (HPLC)method.

The non-polar solvent may preferably be included at a ratio of 5 to 95wt %, more preferably 10 to 90 wt %, even more preferably 40 to 90 wt %,and most preferably 70 to 90 wt %, based on the total weight of the thinfilm precursor and the non-polar solvent.

Injection of the non-polar solvent at a content exceeding the upperlimit described above may cause impurities, thereby increasing theresistance and number of impurities in the thin film, while injection ata content below the lower limit may cause the effect of improvement ofthe step coverage and reduction of impurities such as chlorine (Cl)ions, to be obtained through addition of the solvent, to be small.

In the method for forming a thin film, for example, the reduction rateof a thin film growth rate (Å/cycle) per cycle calculated by Equation 1below may be −5% or less, preferably −10% or less, more preferably −20%or less, even more preferably −30% or less, still more preferably −40%or less, and most preferably −45% or less. Within this range, excellentstep coverage and film thickness uniformity may be achieved.

Reduction rate of thin film growth rate per cycle (%)=[(thin film growthrate per cycle when growth inhibitor for forming thin film is used—thinfilm growth rate per cycle when growth inhibitor for forming thin filmis not used)/thin film growth rate per cycle when growth inhibitor forforming thin film is not used]×100  [Equation 1]

In the method for forming a thin film, the residual halogen intensity(c/s) of the thin film formed after 200 cycles, which is measured basedon SIMS, may preferably be 10,000 or less, more preferably 8,000 orless, even more preferably 7,000 or less, and still more preferably6,000 or less. Within this range, excellent prevention of corrosion anddeterioration may be achieved.

In the present disclosure, the purging is preferably performed at 1,000to 10,000 sccm, more preferably at 2,000 to 7,000 sccm, and still morepreferably at 2,500 to 6,000 sccm. Within this range, the thin filmgrowth rate per cycle may be reduced to a desirable range and theprocess byproducts may be reduced.

The atomic layer deposition (ALD) process is very beneficial topreparation of an integrated circuit (IC) that requires a high aspectratio, and particularly has advantages such as excellent stepconformality and uniformity, precise thickness control, and the like,due to the self-limiting thin film growth mechanism.

The method for forming a thin film may be performed, for example, at adeposition temperature in the range of 50 to 900° C., preferably at adeposition temperature in the range of 300 to 700° C., more preferablyat a deposition temperature in the range of 350 to 600° C., even morepreferably at a deposition temperature in the range of 400 to 550° C.,and still more preferably at a deposition temperature in the range of400 to 500° C. Within this range, it is possible to achieve growth of athin film with excellent film quality while realizing the ALD processcharacteristics.

The method for forming a thin film may be performed, for example, at adeposition pressure in the range of 0.1 to 10 Torr, preferably at adeposition pressure in the range of 0.5 to 5 Torr, and most preferablyat a deposition pressure in the range of 1 to 3 Torr. Within this range,it is possible to obtain a thin film having uniform thickness.

In the present disclosure, the deposition temperature and depositionpressure may be measured as the temperature and pressure to be formed inthe deposition chamber, or may be measured as the temperature andpressure to be applied to the substrate in the deposition chamber.

The method for forming a thin film may preferably comprise steps ofraising the temperature in the chamber to a deposition temperaturebefore the injection of the growth inhibitor for forming a thin filminto the chamber; and/or injection and purging of an inert gas into thechamber before the injection of the growth inhibitor for forming a thinfilm.

In addition, the present disclosure may comprise an apparatus forpreparing a thin film capable of implementing the method for forming athin film described in the present disclosure, the apparatus forpreparing a thin film comprising an atomic layer deposition (ALD)chamber, a first vaporizer for vaporizing the growth inhibitor forforming a thin film, a first transfer unit for transferring thevaporized growth inhibitor into the ALD chamber, a second vaporizer forvaporizing a metal film precursor, metal oxide film precursor, metalnitride film precursor or silicon nitride film precursor, and a secondtransfer unit for transferring the vaporized thin film precursor intothe ALD chamber. Here, the vaporizer and the transfer unit to beemployed are not particularly limited, as long as they are generallyused in the art to which the is present disclosure pertains.

As a specific example, the method for forming a thin film is describedas follows.

First, the substrate on which the thin film is to be formed is placed ina deposition chamber capable of atomic layer deposition.

The substrate may comprise a semiconductor substrate such as a siliconsubstrate, silicon oxide, or the like.

The substrate may further comprise a conductive layer or an insulatinglayer formed thereon.

In order to deposit the thin film on the substrate placed in thedeposition chamber, the above-described growth inhibitor for forming athin film and the thin film precursor or a mixture of the film precursorcompound and the non-polar solvent are prepared, respectively.

Then, the prepared inhibitor for forming a thin film is injected intothe vaporizer and converted into a vapor phase, transferred to thedeposition chamber, and then adsorbed on the substrate, after which theremaining unadsorbed inhibitor is purged.

Next, the prepared film precursor compound or a mixture of the thin filmprecursor and the non-polar solvent is injected into the vaporizer andconverted into a vapor phase, transferred to the deposition chamber, andthen adsorbed on the substrate, after which the unadsorbed compositionfor forming a thin film is purged.

In the present disclosure, as the method employed for transferring theinhibitor for forming a thin film, the film precursor compound, and thelike, to the deposition chamber, for example, a vapor flow control (VFC)method for transferring a volatilized gas through utilization of a massflow controller (MFC), or a liquid delivery system (LDS) method fortransferring a liquid through utilization of a liquid mass flowcontroller (LMFC), and preferably, the LDS method, may be employed.

Here, as a transfer gas or diluent gas for moving the inhibitor forforming a thin film, the film precursor, and the like, onto thesubstrate, one or a mixture of two or more gases selected from argon(Ar), nitrogen (N₂), and helium (He) may be used, but the gas is notlimited thereto.

In the present disclosure, the purge gas may be, for example, an inertgas, and preferably, the transfer gas or dilution gas above.

Next, the reaction gas is supplied. The reaction gas is not particularlylimited as long as it is a reaction gas generally used in the art towhich the present disclosure pertains, and may preferably comprise areducing agent, a nitriding agent, or an oxidizing agent. A metal thinfilm is formed through reaction of the reducing agent with the filmprecursor adsorbed on the substrate, while a metal nitride thin film isformed through reaction of the nitriding agent and a metal oxide thinfilm is formed through reaction of the oxidizing agent.

Preferably, the reducing agent may be ammonia gas (NH₃) or hydrogen gas(H₂), the nitriding agent may be nitrogen gas (N₂), and the oxidizingagent may be one or more selected from the group consisting of H₂O,H₂O₂, O₂, O₃, and N₂O.

Next, the unreacted residual reaction gas is purged by using the inertgas. Thus, not only the excess reaction gas but also any generatedbyproducts may be removed together.

As described above, a unit cycle may comprise steps of adsorbing theinhibitor for forming a thin film on the substrate, purging theunadsorbed inhibitor for forming a thin film, adsorbing the filmprecursor on the substrate, purging the unadsorbed composition forforming a thin film, supplying a reaction gas, and purging the residualreaction gas, and the unit cycle may be repeated to form a thin filmhaving a desired thickness.

The unit cycle may be performed, for example, from 100 to 1000 times,preferably 100 to 500 times, and more preferably 150 to 300 times.Within this range, the desired thin film characteristics may be wellexpressed.

FIG. 1 is a process chart illustrating the conventional ALD process, andFIG. 2 is a flowchart illustrating the ALD process according to anembodiment of the present disclosure. Referring to FIG. 1, as in theconventional ALD process, when protection of the surface of thesubstrate is not achieved by first adsorbing the growth inhibitor forforming a thin film according to the present disclosure beforeadsorption of the film precursor (for example, TiCl₄), processby-products such as HCl remain in the thin film (for example, TiN) dueto reaction with the reaction gas (for example, NH₃), and thus theperformance of the substrate is lowered due to corrosion ordeterioration. However, as shown in FIG. 2, when the surface of thesubstrate is protected (achieving surface protection; SP) by firstadsorbing the growth inhibitor (TSI) for forming a thin film accordingto the present disclosure before adsorption of the film precursor (forexample, TiCl₄), the process by-products such as HCl generated throughreaction with the reaction gas (for example, NH₃) at the time offormation of the thin film (for example, TiN) are removed together withthe growth inhibitor for forming a thin film, thereby preventingcorrosion or deterioration of the substrate, and further, appropriatelylowering the thin film growth rate per cycle to improve the stepcoverage and film thickness uniformity.

The growth inhibitor for forming a thin film of the present disclosureis characterized by a compound represented by Chemical Formula 1 below.

AnBmXo  [Chemical Formula 1]

wherein A is carbon or silicon, B is hydrogen or a C1-C3 alkyl, X is ahalogen, n is an integer from 1 to 15, o is an integer of 1 or more, andm is from 0 to 2n+1. In this case, side reactions occurring duringformation of the thin film may be suppressed to lower the thin filmgrowth rate while also achieving removal of process byproducts in thethin film, and thus corrosion or deterioration may be reduced and stepcoverage and thickness uniformity of a thin film may be greatly improvedeven when the thin film is formed on a substrate having a complexstructure.

In Chemical Formula 1, B is preferably hydrogen or methyl, n ispreferably an integer from 2 to 15, more preferably an integer from 2 to10, even more preferably an integer from 2 to 6, and still morepreferably an integer from 4 to 6. Within this range, an effect ofremoving the process byproducts may be large and excellent step coveragemay be achieved.

In Chemical Formula 1, X may be one or more selected from the groupconsisting of, for example, F, Cl, Br and I, and is preferably Cl(chlorine), in which case side reactions may be suppressed and processby-products may be effectively removed.

In Chemical Formula 1, o may preferably be an integer from 1 to 5, morepreferably an integer from 1 to 3, and even more preferably may be 1 or2. Within this range, an effect of reducing the deposition rate may belarge, which is more effective for improving the step coverage.

M is preferably from 1 to 2n+1, and more preferably from 3 to 2n+1.Within this range, the effect of removing the process byproducts may belarge and excellent step coverage may be achieved.

The compound represented by Chemical Formula 1 may preferably be abranched, cyclic or aromatic compound, and may be specifically one ormore selected from the group consisting of 1,1-dichloroethane,1,2-dichloroethane, dichloromethane, 2-chloropropane, 1-chloropropane,1,2-dichloropropane, 1,3-dichloropropane, 2,2-dichloropropane,1-chloropentane, 2-chloropentane, 3-chloropentane, chlorocyclopentane,n-butylchloride, tert-butyl chloride, sec-butyl chloride, isobutylchloride, 1,2-dichlorobenzene, 1,4-dichlorobenzene,trimethylchlorosilane, trichloropropane, 2-chloro-2-methylbutane,2-methyl-1-pentane, and the like. In this case, there are advantages inthat the effect of removing the process byproducts is large andexcellent step coverage is achieved.

The compound represented by Chemical Formula 1 is preferably used in anatomic layer deposition (ALD) process, and in this case, there areadvantages in that the compound acts as a growth inhibitor toeffectively protect the surface of the substrate and effectively removeprocess byproducts without interfering with adsorption of the filmprecursor.

The compound represented by Chemical Formula 1 is preferably a liquid atroom temperature (22° C.), may have a density of 0.8 to 1.5 g/cm³, avapor pressure (20° C.) of 1 to 300 mmHg, and solubility in water (25°C.) of 200 mg/L or less. Within this range, excellent step coverage andthickness uniformity may be achieved.

More preferably, the compound represented by Chemical Formula 1 may havea density of 0.85 to 1.3 g/cm³, a vapor pressure (20° C.) of 1 to 260mmHg, and solubility in water (25° C.) of 160 mg/L or less. Within thisrange, excellent step coverage and thickness uniformity of the thin filmmay be achieved.

The semiconductor substrate of the present disclosure is characterizedby being prepared by the method for forming a thin film of the presentdisclosure, and in this case, it is possible to appropriately lower thethin film growth rate and also remove process byproducts in the thinfilm by suppressing side reactions, thereby preventing corrosion ordeterioration and greatly improving the step coverage and thicknessuniformity of the thin film.

The prepared thin film preferably has a thickness of 20 nm or less, aspecific resistance value of 0.1 to 400μΩ·cm, a halogen content of10,000 ppm or less, and a step coverage of 90% or more. Within thisrange, the prepared thin film may have excellent performance as adiffusion barrier film, and the corrosion of a metal wiring material maybe reduced, but the present disclosure is not limited thereto.

The thin film may have, for example, a thickness of 5 to 20 nm,preferably 10 to 20 nm, even more preferably 15 to 18.5 nm, and stillmore preferably 17 to 18.5 nm. Within this range, the thin film may haveexcellent characteristics.

The thin film may have a specific resistance value of, for example, 0.1to 400 μΩ·cm, preferably 50 to 400 μΩ·cm, more preferably 200 to 400μΩ·cm, even more preferably 300 to 400 μΩ·cm, still more preferably 330to 380μΩ·cm, and most preferably 340 to 370μΩ·cm. Within this range, thethin film may have excellent characteristics.

The thin film may have a halogen content of more preferably 9,000 ppm orless, or 1 to 9,000 ppm; even more preferably 8,500 ppm or less, or 100to 8,500 ppm; and still more preferably 8,200 ppm or less, or 1,000 to8,200 ppm. Within this range, the thin film may have excellentcharacteristics and the corrosion of the metal wiring material may bereduced.

The thin film may have, for example, a step coverage of 80% or more,preferably 90% or more, and more preferably 92% or more. Within thisrange, even if a thin film has a complex structure, the thin film iscapable of being easily deposited on the substrate, thereby enablingapplication to a next generation semiconductor device.

The prepared thin film may be, for example, a metal nitride thin film ora metal oxide film, and as a specific example, a TiN thin film or a TiO₂thin film.

Hereinafter, preferable Examples of the present disclosure will bedescribed in order to facilitate understanding of the presentdisclosure. However, it will be apparent to those skilled in the artthat the following Examples are provided only to illustrate the presentdisclosure, various changes and modifications can be made within thespirit is and the scope of the disclosure, and these variations andmodifications are included within the scope of the appended claims.

EXAMPLES Examples 1 to 7

A growth inhibitor for forming a thin film, shown in Table below, andTiCl₄, as a film precursor, were prepared, respectively. The preparedgrowth inhibitor for forming a thin film was placed in a canister andsupplied to a vaporizer heated at 150° C. at a flow rate of 0.05 g/minusing a liquid mass flow controller (LMFC) at room temperature. Thevaporized growth inhibitor for forming a thin film, converted into thevapor phase in the vaporizer, was injected into a deposition chamberloaded with a substrate for 3 seconds, after which argon purging wasperformed by supplying argon gas at 3000 sccm for 6 seconds. Here, thepressure in the reaction chamber was controlled to be 1.3 Torr. Next,the prepared TiCl₄ was placed in a separate canister and supplied to aseparate vaporizer heated at 150° C. at a flow rate of 0.05 g/min usingan LMFC at room temperature. The vaporized TiCl₄′ converted to the vaporphase in the vaporizer, was injected into the deposition chamber for 3seconds, after which argon purging was performed by supplying argon gasat 3000 sccm for 6 seconds. Here, the pressure in the reaction chamberwas controlled to be 1.3 Torr. Next, ammonia as a reaction gas wasinjected into the reaction chamber for 5 seconds, and then argon purgingwas performed for 10 seconds. Here, the substrate on which a metal thinfilm was to be formed was heated to 460° C. This process was repeated200 times to form a TiN thin film as a self-limiting atomic layer.

TABLE 1 Growth inhibitor for forming a thin film Example 12-chloro-2-methylbutane Example 2 n-butyl chloride Example 3trimethylchlorosilane Example 4 2-chloropropane Example 51,2,3-trichloropropane Example 6 2-methyl-1-pentane Example 71,2-dichlorobenzene

Comparative Example 1

A TiN thin film was formed on a substrate in the same manner as inExample 1, except that the growth inhibitor for forming a thin film wasnot employed and thus the step of purging the unadsorbed growthinhibitor for forming a thin film was omitted.

Comparative Examples 2 and 3

A TiN thin film was formed on a substrate in the same manner as inExample 1, except that pentane or cyclopentane was used instead of thegrowth inhibitor for forming a thin film described in Table 1 above.

Experimental Example

1) Deposition Evaluation

Referring to Table 2 below, Example 1, in which chloro-2-methylbutanewas used as the growth inhibitor for forming a thin film, was comparedwith Comparative Example 1, in which the growth inhibitor for forming athin film was not included. As a result, the deposition rate of Example1 was 0.20 Å/cycle, which represents a reduction of over 55.5% whencompared with the deposition rate of Comparative Example 1. It could beconfirmed that Examples 2 to 7 also had deposition rates similar to thatof Example 1. Further, it could be confirmed that Comparative Examples 2and 3, using pentane or cyclopentane instead of the growth inhibitor forforming a thin film according to the present disclosure, also had adeposition rate equal to that of Comparative Example 1. Here, thereduction in deposition rate means that the CVD depositioncharacteristics are changed to ALD deposition characteristics, and thusmay be used as an index for improvement of the step coveragecharacteristics.

TABLE 2 Deposition Rate Growth Inhibitor (Å/cycle) Example 12-chloro-2-methylbutane 0.20 Example 2 n-butyl chloride 0.31 Example 3trimethylchlorosilane 0.28 Example 4 2-chloropropane 0.20 Example 51,2,3-trichloropropane 0.32 Example 6 2-methyl-1-pentane 0.28 Example 71,2-dichlorobenzene 0.30 Comparative X 0.45 Example 1 ComparativePentane 0.45 Example 2 Comparative Cyclopentane 0.45 Example 3

In addition, as shown in Table 3, it could be confirmed that thedeposition rate was continuously reduced according to the feeding amountof chloro-2-methylbutane, the growth inhibitor for forming a thin film.Here, Example 1-1 was performed in the same manner as in Example 1,except for the feeding amount of the growth inhibitor for forming a thinfilm per cycle.

TABLE 3 Comparative Example 1 Example 1 Example 1-1 Feeding amount per 01.6 3.2 ALD cycle (mg/cycle) Deposition rate 0.45 0.20 0.02 (Å/cycle)

2) Impurity Reduction Characteristics

SIMS analysis was performed to compare the impurity reductioncharacteristics, that is, the process byproduct reductioncharacteristics, of the TiN thin films deposited in Example 1 andComparative Example 1, the results of which are shown in Table 4 below.

TABLE 4 Comparative Example 1 Example 1 Feeding amount per 1.6 0 ALDcycle (mg/cycle) Cl intensity (c/s) 5907.05 17270.25

As shown in Table 4, it could be confirmed that the impurities ofExample 1, in which the growth inhibitor for forming a thin filmaccording to the present disclosure was employed, were reduced to about1/3 the amount in comparison to Comparative Example 1, in which thegrowth inhibitor was not employed.

Further, FIG. 3 is a graph showing the change in thickness of the thinfilm according to the increase in atomic layer deposition (ALD) cycle ofExample 7 (SP—TiCl₄) and Comparative Example 1 (TiCl₄) of the presentdisclosure, wherein it could be confirmed that the thickness of the thinfilm in Example 7 became significantly thinner.

In addition, FIG. 4 is a graph illustrating the change in depositionrate according to the feeding time of a growth inhibitor (SP) forforming a thin film per ALD cycle of Examples 7-1 to 7-3 and ComparativeExample 1 of the present disclosure, wherein it could be confirmed thatwhen the inhibitor for forming a thin film according to the presentdisclosure was not used, as in Comparative Example 1, the depositionrate was 0.45 Å/cycle, whereas in Examples 7-1, 7-2, and 7-3, in whichthe growth inhibitor for forming a thin film according to the presentdisclosure was injected in an amount of 0.7 sec, 1 sec, and 2 sec,respectively, the deposition rate was significantly thinned to 0.35Å/cycle, 0.2 Å/cycle, and 0.1 Å/cycle, respectively. Here, Examples 7-1,7-2, and 7-3 were performed in the same manner as in Example 7, exceptfor the feeding amount of the growth inhibitor for forming a thin film.

3) Step Coverage Characteristics

The step coverage of TiN thin films deposited in Example 1 andComparative Example 1 were confirmed by TEM, the results of which areshown in Table 5 below and FIG. 5.

TABLE 5 Example 1 Comparative 1 Step coverage rate (%) 92% 78%

As shown in Table 5, it could be confirmed that the step coverage ofExample 1, in which the growth inhibitor for forming a thin filmaccording to the present disclosure was employed, was significantlyhigher than that of Comparative Example 1, in which the growth inhibitorwas not employed.

In addition, referring to the TEM images shown in FIG. 5, it could beconfirmed that in view of the thickness uniformity of the top andbottom, the step conformality of the TiN thin film deposited in Example1 (SP—TiCl₄) was more excellent as compared to the TiN thin filmdeposited in Comparative Example 1 (TiCl₄).

Additional Example 1

A zirconium oxide film (ZrO₂ thin film) was formed by the same method asin Example 1 above, except that tris(dimethylamino)cyclopentadienylzirconium (CpZr) was used as a film precursor instead of TiCl₄, thegrowth inhibitor for forming a thin film was injected into the chamberat an amount of 12 mg/sec, ozone was used as a reaction gas instead ofammonia, and the substrate on which the metal thin film was to be formedwas heated to 280 to 340° C.

Additional Example 2

A zirconium oxide film (ZrO₂ thin film) was formed by the same method asin Additional Example 1, except that the growth inhibitor for forming athin film was injected into the chamber at an amount of 2.3 mg/sec for 1to 7 seconds, respectively, and the substrate on which the metal thinfilm was to be formed was heated to 310° C.

Additional Comparative Example 1

A zirconium oxide film (ZrO₂ thin film) was formed by the same method asin Additional Example 1, except that the growth inhibitor for forming athin film was not employed.

The deposition rate, reduction rate (%), and thickness uniformity (%)were measured for the zirconium oxide films deposited in AdditionalExamples 1 and 2 and Additional Comparative Example 1, the results ofwhich are shown in Table 6 below and FIG. 6. Here, the thicknessuniformity (%) was calculated by Equation 2, as follows:

Thickness uniformity (%)=[(MAX−MIN)/(2*AVERAGE)]*100%  [Equation 2]

wherein the MAX, MIN, and AVERAGE represent the maximum value, theminimum value, and the average value of the thickness, and each opticalthickness was measured using ellipsometer equipment.

TABLE 6 Temp (° C.) 280 290 300 310 320 330 340 Additional SP-CpZr 0.5100.508 0.510 0.510 0.510 0.511 0.510 Example 1 (Å/cycle) reduction 34.635.5 35.9 36.1 36.6 40.1 42.3 rate (%) Uniformity 1.1 2.1 1.6 1.5 1.71.5 1.8 (%) Additional CpZr 0.781 0.788 0.796 0.798 0.805 0.854 0.884Comparative (Å/cycle) Example 1 Uniformity 1.4 1.1 1.2 1.6 3.1 4.3 3.8(%)

As shown in Table 6, in the zirconium oxide film (Additional Example 1)formed by using the growth inhibitor for forming a thin film accordingto the present disclosure, as compared to the zirconium oxide film(Additional Comparative Example 1) formed without employment of thegrowth inhibitor according to the present disclosure, it could beconfirmed that the thin film thickness per ALD cycle according to thedeposition temperature was very constant at 0.508 to 0.511 Å, whilesimultaneously, the reduction rate was greatly decreased to the range of34.6 to 42.3%, and further, the film thickness uniformity was in therange of 1.1 to 2.1%, indicating a very small fluctuation range.

Further, FIG. 6 is a graph illustrating the change in deposition rate(Å/cycle) according to the feeding time (s) of the growth inhibitor (SP)for forming a thin film per ALD cycle for Additional Example 2 andAdditional Comparative Example 1 of the present disclosure, wherein itcould be confirmed that when the inhibitor for forming a thin filmaccording to the present disclosure was not employed, as in AdditionalComparative Example 1, the deposition rate per cycle was about 0.8Å/cycle, whereas in Additional Example 2 in which the growth inhibitorfor forming a thin film according to the present disclosure was injectedfor 1 second, 3 seconds, 5 seconds, and 7 seconds, respectively, thedeposition rate was significantly lowered to about 0.56 Å/cycle, 0.52Å/cycle, 0.51 Å/cycle, and 0.50 Å/cycle, respectively. Here,SP—P—SF—P—OF—P means 1 cycle comprising injection of the growthinhibitor (SP) for forming a thin film, injection of a purge gas (P),injection of a thin film precursor (SF), injection of a purge gas (P),injection of a reaction gas (OF), and injection of a purge gas (F),X-2X-5-10-3-6 means the feeding time S of each step, and X is an integerof 0 to 7.

As set forth above, according to the present disclosure, it is possibleto provide a method for forming a thin film capable of suppressing sidereactions and reducing a deposition rate to appropriately lower a thinfilm growth rate while also removing process byproducts in the thinfilm, thereby preventing corrosion or deterioration and greatlyimproving step coverage and thickness uniformity of the thin film, evenwhen the thin film is formed on a substrate having a complex structure.

What is claimed is:
 1. A method for forming a thin film comprising stepsof: i) adsorbing a growth inhibitor for forming a thin film on a surfaceof a substrate; and ii) adsorbing a metal film precursor, metal oxidefilm precursor, metal nitride film precursor or silicon nitride filmprecursor on a surface of a substrate on which the growth inhibitor isadsorbed, wherein the growth inhibitor for forming a thin film isrepresented by Chemical Formula 1 below, and the metal is at least oneselected from a group consisting of tungsten, cobalt, chrome, aluminum,hafnium, vanadium, niobium, germanium, lanthanide, actinoids, gallium,tantalum, zirconium, ruthenium, copper, titanium, nickel, iridium andmolybdenum.AnBmXo  [Chemical Formula 1] wherein A is carbon or silicon, B ishydrogen or a C1-C3 alkyl, X is a halogen, n is an integer of 1 to 15, ois an integer of 1 or more, and m is 0 to 2n+1.
 2. The method forforming a thin film of claim 1, wherein in the step of i) adsorbing thegrowth inhibitor for forming a thin film on the surface of thesubstrate, the feeding time for the growth inhibitor is 1 to 10 seconds.3. The method for forming a thin film of claim 1, wherein the step of i)adsorbing the growth inhibitor for forming a thin film on the surface ofthe substrate comprises a step of injecting the growth inhibitor forforming a thin film into an atomic layer deposition (ALD) chamber andadsorbing the growth inhibitor onto a surface of a loaded substrate. 4.The method for forming a thin film of claim 1, wherein the step of i)adsorbing the growth inhibitor for forming a thin film on the surface ofthe substrate comprises a step of purging the remaining inhibitorunadsorbed on the surface of the substrate for forming the thin filmwith a purge gas.
 5. The method for forming a thin film of claim 1,wherein the step of ii) adsorbing a film precursor may preferablecomprise a step of purging the remaining unadsorbed film precursor witha purge gas.
 6. The method for forming a thin film of claim 1, furthercomprising steps of supplying a reaction gas after adsorption of a filmprecursor on the surface of the substrate, and purging reactionbyproducts of the film precursor and the reaction gas with a purge gas.7. The method for forming a thin film of claim 6, wherein the reactiongas comprises a reducing agent, a nitriding agent, or an oxidizingagent.
 8. The method for forming a thin film of claim 1, wherein thegrowth inhibitor for forming a thin film and the film precursor aretransferred into the ALD chamber by a vapor flow control (VFC) method, adelivery liquid injection (DLI) method, or a liquid delivery system(LDS) method.
 9. The method for forming a thin film of claim 1, whereinthe ratio of the feeding amount (mg/cycle) between the growth inhibitorfor forming a thin film and the film precursor in the ALD chamber isfrom 1:1.5 to 1:20.
 10. The method for forming a thin film of claim 1,wherein X is chlorine (Cl).
 11. The method for forming a thin film ofclaim 1, wherein o is an integer from 1 to
 5. 12. The method for forminga thin film of claim 1, wherein the compound represented by ChemicalFormula 1 is a branched, cyclic or aromatic compound.
 13. The method forforming a thin film of claim 1, wherein the compound represented byChemical Formula 1 is a liquid at room temperature (22° C.), and has adensity of 0.8 to 1.5 g/cm³, a vapor pressure (20° C.) of 1 to 300 mmHg,and solubility in water (25° C.) of 200 mg/L or less.
 14. The method forforming a thin film of claim 1, wherein a reduction rate of a thin filmgrowth rate (Å/cycle) per cycle calculated by the following Equation 1is−5% or less.Reduction rate of thin film growth rate per cycle (%)=[(thin film growthrate per cycle when growth inhibitor for forming thin film is used−thinfilm growth rate per cycle when growth inhibitor for forming thin filmis not used)/thin film growth rate per cycle when growth inhibitor forforming thin film is not used]×100  [Equation 1]
 15. The method forforming a thin film of claim 1, wherein the residual halogen intensity(c/s) of the thin film formed after 200 cycles, which is measured basedon SIMS, is 10,000 or less.
 16. An apparatus for preparing a thin filmcomprising: an atomic layer deposition (ALD) chamber, a first vaporizerfor vaporizing the growth inhibitor for forming a thin film, a firsttransfer unit for transferring the vaporized growth inhibitor into theALD chamber, a second vaporizer for vaporizing a metal film precursor,metal oxide film precursor, metal nitride film precursor or siliconnitride film precursor, and a second transfer unit for transferring thevaporized precursor into the ALD chamber.